A Funes adviser told me that it was doctored; Funes was never in that location with Mr. Chávez. Dirty campaigning, on both sides, has been a big theme in the race.

Funes’s opponent was a former police chief whose slogan was “Vote with Wisdom.” The left shot back with a billboard of a doughnut-eating cop from “The Simpsons”: “Vote with wisdom: Don’t vote for the ex-cop.”